High Efficiency Video Coding (HEVC), currently under development by the Joint Collaborative Team on Video Coding (JCT-VC) formed by ISO/IEC Moving Picture Expert Group (MPEG) and ITU-T Video Coding Experts Group (VCEG), is a video compression standard projected to be finalized in 2012. Similar to previous video coding standards, HEVC includes basic functional modules such, as intra/inter prediction, transform, quantization, in-loop filtering, and entropy coding.
HEVC defines Coding Units (CUs) as picture sub-partitions that take the form of rectangular blocks having variable sizes. Within each CU, a quad-tree based splitting scheme specifies the CU partition pattern. HEVC also defines Prediction Units (PUs) and Transform Units (TUs) that specify how a given CU is to be partitioned for prediction and transform purposes, respectively. After intra or inter prediction, transform operations are applied to residual blocks to generate coefficients. The coefficients are then quantized, scanned into one-dimensional order and, finally, entropy encoded.
HEVC is expected to include a Scalable Video Coding (SVC) extension. An HEVC SVC bitstream provides several subset bitstreams representing the source video content at different spatial resolutions, frame rates, quality, bit depth, and so forth. Scalability is then achieved using a multi-layer coding structure that, in general, includes a Base Layer (BL) and at least one Enhancement Layer (EL). This permits a picture, or portions of a picture such as a PU, belonging to an EL to be predicted from lower layer pictures (e.g., a BL picture) or from previously coded pictures in the same layer. In conventional approaches, prediction, for a current PU is performed with respect to PUs of pictures within the same layer. For instance, residual prediction for an EL PU is conventionally performed with respective to PUs of the same EL and not of another EL or of the BL.